Why would .co.nz merge with Australia?
How would it work.
Of course the countries are never going to merge.
Just for fun, hypothetically both extensions would stand. No way would the owner of the .co.nz have any claim to an already existing domain unless they were to register it as a trademark in Australia.
No they don'tif a Country merge, they merge too.
No they don't
Many countries including australia has additional cctlds besides the main one
.cc .nf plus others are already allocated to australian territories.
.nz would/could remain active